AEROSONDE

PACJET presents an opportunity for realistic field testing of a promising UAV,
the AEROSONDE. The goal is to conduct at least one successful flight from Hawaii
to the west coast in the context of a significant storm and with over-the-horizon
communication with the UAV. The capabilities of the AEROSONDE
appear to be well suited to PACJET's goal of measuring the low-level jet.

NOAA P-3

In flight reconnaissance report
Observations from the P-3 aircraft will be synthesized into a brief report that contains
measurements of several key aspects of storms 200-500 km offshore, or roughly 6-12 h before
the heaviest rain is anticipated to reach shore. The types of measurements are based on the
unique array of instruments on board the P-3, including a surveillance radar on its belly, a
Doppler radar on its tail, a scanning radar altimeter to measure sea state from aloft,
dropsondes, and low-altitude flights to pinpoint the low-level jet and its water vapor content.
The message will contain information that forecasters and the forecast user communities
identified as key to the watch/warning program and to emergency management at two
planning workshops held in 1999 and 2000. Before a flight, these groups will be alerted that
such reports will become available in the next 24 hours. During a flight the reconnaissance
message will be posted on the PACJET web page roughly every 2 hours.

Developmental flight report format.

Tail Radar Data
The tail radar on the P-3 is a Doppler radar and provides detailed measurements of the
vertical and kinematic (wind) structure of storms in a swath roughly 80 km wide (40 km on
either side of the aircraft). These data have proved especially useful in research, and will
provide real-time measurements of the intensity of precipitation and depth of the storm, as
well as the height of the freezing level that will be included in the reconnaissance message.

Data from the P3 Tail radar during CALJET.

Fuselage Radar Data
The belly radar is not a Doppler radar, but it provides radar reflectivity measurements out to a
range of roughly 200 km. This capability allows on-board assessment of the position,
orientation, and strength of rain bands. Rain band motion can be determined by tracking
them over roughly an hour.

Data from the P3 Fuselage Radar during CALJET.

PACJET Flight data system
The flight data system currently installed on the P3 will allow the flight reconnaissance
report to be transmitted twice an hour. Efforts are being made to acquire an satellite
transmission system which would provide greater bandwidth and two-way communication between
the plane in flight and the operations center.

Schematic of P3 data system.

Wind Profiler Network

Profiler deployment for CRPAQS.

Satellite Products

Cooperative Institute for Meteorological
Satellite Studies (CIMSS)Real-time GOES winds.
Specialized GOES wind products based on a feature tracking technique
were produced by CIMSS as part of the CALJET experiment in 1998. A
unique component of this data set is the availability of
super-rapid-scan (1-min sampling) GOES images. These data were used
to assess the impact of shortening the time between images used in
feature tracking. Standard approaches used 30-min between samples,
but tests in tropical storms had suggested more frequent sampling
could improve areal coverage in regions where cloud features had a
shorter lifetime than 30 min. The figures shown here represent the
results of this test using a 5-min lag between images for both IR and
visible channels. These are compared to results using 30 min lag, and
confirm that the areal data coverage increases significantly. Using
statistical internal consistency checks it was determined that the
optimal time lag was about 5-min. Wind vectors calculated using
shorter lags had higher internal variance that resulted from the
increased influence of satellite pointing uncertainty as the distance
between features decreased, i.e., with shorter time lags. Based on
these results, a new GOES scan pattern is being developed that should
provide a set of 3 consecutive 5-minute interval images, once every
hour around the clock during PACJET over the domain shown here.
In addition to the GOES wind products, GOES sounder moisture products
(total precipitable water vapor, and cloud-top pressure) will be
available at 3-hourly intervals.

A number of satellite products and images will be produced at ETL during PACJET
both for large-scale monitoring and algorithm calibration/validation
efforts. Data from numerous operational satellites are currently
archived by ETL and will be used to support the PACJET field program.
Some examples of satellite products planned for PACJET include
individual overpass and daily composite satellite derived estimates of
precipitation, cloud liquid water, total precipitable water, and ocean
surface wind speed from SSM/I passive microwave observations. Other
satellite products will include daily surface wind vectors from the
Quikscat scatterometer and sea surface temperature estimates from GOES
and AVHRR data. An example image of SSM/I derived total precipitable
water with surface wind vectors from QuikScat is shown here. In
addition, mid and upper tropospheric water vapor imagery from the
microwave SSM/T2 and AMSU-B moisture sounders will be available.

S-band data

S-band radar deployed at CALJET

ETL S-band Radar

A new S-band vertical profiler with a coupler option for extending the
dynamic range of the radar's receiver has been developed by the NOAA
Environmental Technology Laboratory and successfully field tested during
CALJET. The 30 dB of added dynamic range provided by the coupler allows
the profiler to record radar reflectivity measurements in
moderate-to-heavy precipitation that otherwise would not have been
possible with this system because of receiver saturation. The radar
hardware, signal processor, and operating software are based on existing
S-band and UHF profiler technology developed at the NOAA Aeronomy
Laboratory. Results from a side-by-side comparison with the NOAA K-band
radar were used to determine the calibration and sensitivity of the
S-band profiler. In a typical cloud profiling mode of operation, the
sensitivity is -14 dBZ at 10 km or -25 dBZ at 3 km. During CALJET, the
profiler was deployed at Cazadero, California, near the crest of the
coastal mountains in a region climatologically prone to flooding. The
profiler was part of an integrated observing system designed for
measuring physical processes associated with orographic precipitation
enhancement. The CALJET S-band dataset is also being applied to the
problem of quantitative precipitation estimation using the WSR-88D
(NEXRAD) network.